If there is not a lot of other sugar in your diet, then what is the problem? Brown sugar is better than white sugar for you, well it is tastier anyhow.
You could try sweet fruit instead with the chicken and pork. Sultanas, raisins, apricots, dates, apples are all sweet fruits that have been used in recipes with chicken, pork and the likes.
I often use apricots, dates and recently kiwi with some of my dishes. Another was pomegranate that added sweetness.
Using dessert apples instead of cooking apples will add sweetness as well.
Otherwise you are looking at things like date syrup and honey to add sweetness. Grape syrup is another that can be used, but they are all just taking the sugar and leaving the fibre behind (except of course honey), so all are use with care so to speak.
As for the butter - well it is better to be using lots of butter than it is lots of refined margarines, and I have always worked on the principle it is better to use less of what you like than more of something you don't like that is supposedly (this week at least) healthier for you!